1. Field of the Invention
The present invention relates to the use of flupirtine or its salts as medicaments in the prophylaxis and therapy of diseases associated with an impairment of the haematopoetic cell system, for example lymphocytes.
2. Background Information
Flupirtine is a known, established, non-opiate analgesic with central action.
Flupirtine expresses its analgesic actions by different mechanisms from the opiate/opioid analgesics (Nickel, B., Postgrad, Med. J. 63 (Suppl.3), 19 (1987); Szelenyi, I., Nickel, B., Borbe, H. O., Brune K., Br. J. Pharmacol. 143, 89 (1989)). Electrophysiological studies have shown that flupirtine is able to influence nociceptive events at the supraspinal level as well as at the spinal level (Carisson, K. H., Jurna, I., Eur. J. Pharmakol. 143, 89 (1987); Bleyer, H., Carlsson, K. H., Erkel, H. J., Jurna, I., Eur. J. Pharmacol. 151, 259 (1988); Nickel, B., Aledter, A., Postgrad Med. J. 63 (Suppl.3) 41 (1987)).
Flupirtine is also used in the therapy of periods of acute pain caused by diseases of the locomotion system.
Furthermore, flupirtine is successfully used in patients with degenerative or rheumatic diseases.
In addition to having good analgesic properties, flupirtine also has muscle-relaxant properties, so that flupirtine can also be used in the treatment of muscular tension, or of diseases caused by muscular tension (DE 40 22 442).
In studies of the muscle relaxant action of flupirtine in rats it was further found that the action of flupirtine can be inhibited by the excitatory amino acid N-methyl-D-aspartate (NMDA). Due to this NMDA antagonistic action, flupirtine is also suitable for the treatment of NMDA mediated diseases of the CNS, such as cerebral ischaemia, neurodegenerative disorders and epileptic fits (DE 43 27 516).
In chemical terms, flupirtine is 2-amino-3-ethoxycarbonylamino-6-(p-fluorobenzylamino)pyridine. The synthesis of flupirtine and its pharmaceutically usable salts is described in the patents DE 17 95 858, DE 31 33 519 and DE 34 16 609.